Add two new routines: fdevname() and fdevname_r().

A more elegant way of obtaining a name of a character device by its file
descriptor on FreeBSD, is to use the FIODGNAME ioctl. Because a valid
file descriptor implies a file descriptor is visible in /dev, it will
always resolve a valid device name.

I'm adding a more friendly wrapper for this ioctl, called fdevname(). It
is a lot easier to use than devname() and also has better error
handling. When a device name cannot be resolved, it will just return
NULL instead of a generated device name that makes no sense.

Discussed with:	kib

1 files changed, 2 insertions, 0 deletions

diff --git a/include/stdlib.h b/include/stdlib.h
index 91be536668b7..5c8e4e363ef0 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -256,6 +256,8 @@ int	 cgetustr(char *, const char *, char **);
 int	 daemon(int, int);
 char	*devname(__dev_t, __mode_t);
 char 	*devname_r(__dev_t, __mode_t, char *, int);
+char	*fdevname(int);
+char 	*fdevname_r(int, char *, int);
 int	 getloadavg(double [], int);
 __const char *
 	 getprogname(void);